1. Field of the Invention
The present invention relates to a film deposition method and a method for manufacturing a semiconductor device.
2. Description of the Related Art
A silicon oxide film is used as an insulating film, a dielectric film or a surface protective film in preparing a semiconductor device such as field effect transistors.
As to a method for forming such a silicon oxide film, the formation has been carried out in a vapor phase process such as a thermal oxidation method, a chemical vapor deposition method (CVD method) and a sputtering method.
Meanwhile, a liquid phase process includes film deposition by means of hydrolysis of an alkoxysilane or the like; and a formation method by mans of oxidization of a polysilazane or the like.
For example, there is disclosed a method for forming a silicon oxide film by forming a coating film containing a polysilane compound and oxidizing the coating film (see, for example, JP-A-2002-246384).
However, with respect to the foregoing methods, the vapor phase process is a method in which in the vapor phase process, it is necessary to use an expensive vacuum system or a dangerous gas raw material. Also, this vapor phase process is a method in which the energy consumption is large due to a high temperature or use of plasma or the like.
Also, the vapor phase process involves problems such as restrictions in size of a substrate on which a film is formed and uniformity.
Furthermore, the liquid phase process involves a problem such as densification of a film.
Also, according to the thermal oxidation method, not only an insulating film having a thickness of several nm can be formed with good control, but its defect density is low as 1010 cm−2 eV−1. However, since this method includes a process of about 1,000° C., glass or an organic material (a resin, for example, polycarbonates, polystyrenes, polyimides, etc.) cannot be used as a substrate material.
Also, according to the CVD method or the sputtering method, the process temperature is lower than that in the method for forming a thermally oxidized film. However, its defect density is high as 1012 cm−2 eV−1, and it is difficult to form an insulating film having a thickness of several nm with good control.
Furthermore, in an insulating film using a polysilazane or the like, which is used for an interlayer insulating film, a low-temperature process of from about 200° C. to 500° C. is possible. However, its defect density is very high.